The present invention relates to stent deployment devices and methods for deploying stents. More particularly, the present invention concerns a stent deployment device and a method for deploying a stent within the alimentary tract using an endoscope.
Endoscopes are effective devices for diagnosing and treating patients with minimal intervention and discomfort and are often used to explore and perform biopsies in such areas as the alimentary tract. In general, an endoscope has a flexible elongated tubular body equipped with a miniature television camera or other viewing device, a light, and a working lumen or channel. The working channel is used to store and deploy a variety of surgical tools for different endoscopic operations.
A stent is a resilient device often used in anchoring vascular grafts and for supporting body openings during the grafting of vessels and tubes of the body during surgery. Also, stents are frequently used, without grafts, for supporting lumenal patency. More recently, artificial (woven or nonwoven polymeric) grafts are used in cardiac, vascular and nonvascular applications to provide extra support. Moreover, stents can be separated into self expanding and plastically deformed stents. A self expanding stent is deployed by its self expanding resilience. A plastically deformed stent is deployed by plastic deformation of the constituent material with a balloon or other such dilating instrument.
Endoscopes are effectively utilized to deploy stents within a body cavity in a minimally invasive manner. In a conventional method, a stent is compressed to fit into the working channel of the endoscope and is delivered to the body cavity to be treated. However, storing a stent within the working channel of an endoscope causes several problems. First, there is a limitation on the size of the stent that can be compressed to fit in the working channel. Because the working channel of the endoscope is often relatively small, a large stent may not fit within the working channel. Thus, this method is not suitable for deploying large stents.
Additionally, fitting a stent in the working channel often results in extreme deformation of the stent when it is deployed to the body cavity. Since stents are made of resilient material, compression within the working channel can cause the stent to become deformed and fail to return to its original shape if strained beyond a certain point. The more the stent gets strained, the more extreme the deformation is likely to be.
Consequently, there is a need for stent deployment systems and methods that provide a solution to aforementioned problems and permit deployment of stents, regardless of size, into body cavities.